| operation | chirurgische Eingriff |
| Operation -en -er | Operation |
| Operation Achilles | Operation Achilles |
| Operation Ajax | Operation Ajax |
| Operation Bagration | Operation Bagration |
| Operation Barbarossa | Unternehmen Barbarossa |
| Operation Blå | Operation Blau |
| Operation Condor | Operation Condor |
| Operation Dragoon | Operation Dragoon |
| Operation Dynamo | Operation Dynamo |
| Operation Entebbe | Operation Entebbe |
| Operation Fenix | Operation Phoenix |
| Operation Flashpoint | Operation Flashpoint |
| Operation Frühlingserwachen | Plattenseeoffensive |
| Operation Greif | Unternehmen Greif |
| Operation Highjump | Operation Highjump |
| Operation Husky | Operation Husky |
| Operation Ivy | Operation Ivy |
| Operation kjoltyg | Unternehmen Petticoat |
| Operation Market Garden | Operation Market Garden |
| Operation Mars | Operation Mars |
| Operation Merkur | Luftlandeschlacht um Kreta |
| Operation Neptune | Operation Neptune |
| Operation Nordwind | Operation Nordwind |
| Operation Northwoods | Operation Northwoods |
| Operation Overlord | Operation Overlord |
| Operation Reinhard | Aktion Reinhardt |
| Operation Rösselsprung | Operation Rösselsprung |
| Operation Seelöwe | Unternehmen Seelöwe |
| Operation Sledgehammer | Operation Sledgehammer |
| Operation Sommarregn | Operation Sommerregen |
| Operation Stella Polaris | Operation Stella Polaris |
| Operation Storm | Militäroperation Oluja |
| Operation Tannenbaum | Operation Tannenbaum |
| Operation Tannenberg | Unternehmen Tannenberg |
| Operation Torch | Operation Torch |
| Operation Vigilant Resolve | Operation Vigilant Resolve |
| Operation Weserübung | Unternehmen Weserübung |
| Operations Support System | Operations Support System |
| Operationsförstärkare | Operationsverstärker |
| Operationssystem | Betriebssystem |
| operationsverktyg | Besteck |
| operativsystem | Betriebssystem |
| Operativsystemkärna | Betriebssystemkern |
| Operator | Operator |
| Operatorprioritet | Operatorrangfolge |
| operatris | Maschinenbedienerin |
| operatör | Maschinenbediener |
| operera | einen chirurgischen Eingriff vornehmen an |
| opererbar | operabel |
| operett | Operette |
| opersonlig | unpersönlich |
| Opex | Opex |
| Ophelia | Ophelia |
| opiat | Betäubungsmittel |
| Opievallmo | Schlafmohn |
| opinionsbildning | Meinungsbildung |
| opinionsforskare | Demoskop |
| opinionsforskning | Demoskopie |
| opinionsundersökning | Meinungsumfrage |
| Opioid | Opioid |
| Opipramol | Opipramol |
| opium | Opium |
| opiumdroppar | Laudanum |
| Opiumkrigen | Opiumkriege |
| Opkonst | Op-Art |
| oplanerad | zufällig |
| Opole | Oppeln |
| Opole vojvodskap | Woiwodschaft Oppeln |
| opolerad | schroff |
